Prosthodontics & Occlusion · patient case question
During RPD design, what is the primary purpose of the dental surveyor?
Patient case: A denture that will not stay put
demo: 71-year-old male
chief: His upper denture drops when he speaks and food collects under it. He also has a sore lump at the front.
history: He has worn the same maxillary complete denture for fourteen years and has never had it relined. Only the mandibular anterior teeth from 22 to 27 remain.
meds: None relevant.
findings: The maxillary anterior ridge is displaceable and mobile on palpation while the posterior ridge is firm. A folded, fibrous ridge of tissue lies in the labial sulcus adjacent to the denture flange. The mandibular anterior teeth show generalised wear.
Show answer and explanation
Correct answer: B. To identify and measure undercuts and establish a path of insertion
- A. The occlusal plane is assessed clinically and on articulated casts.
- B. Correct. The surveyor holds the cast in a fixed relationship to a vertical analysing rod so that the height of contour can be marked, the path of insertion determined, and the depth of undercut measured with calibrated gauges of 0.01, 0.02 and 0.03 inches. Everything about clasp design flows from that survey.
- C. Vertical dimension is established clinically using rest position, phonetics and facial measurement, not on a surveyor.
- D. Centric relation is recorded clinically with record bases and rims and transferred to an articulator.
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